Ringflash adapter anyone had any experience?

I have just brought a ringflash adapter to use with my canon 580ex and my 5d.

I am a commercial photographer specialising in people/fashion/weddings.

I was very excited about this device as it looks like it should give fully auto operations on a true ringflash thus making it hand holdable and quick to use. Important as I like to shoot spontaneously

I have used it so far in 2 types of situation

Out doors as fill in flash in combination with diffusers and reflectors

As a main lighsource in low light conditions.

The jury is still out for me. I like colourful saturated images and it seems as if the images are a little flat or low in saturation when using this device.

Has anyone else used this device or has any experience of using ringflash of another type?